your efforts to learn OO and Arduino at the same time will lead to endless frustration.
A well-written and structured pure C program for an embedded project will probably be just as maintainable and manageable as its well-written C++ counterpart.
If I am not wrong the C++ is barely used in embedded programming , C is the facto language. So I want to ask : what is the real advantage of C++ classes which is the main difference to C ?
Why wouldn't you allow yourself to use them?